SALT: Solar and Alternative Technologies Research Experience – 2019 – 2023

This project will investigate the use of coke for sequestration of CO2. The delayed coker receives heavy material left over after crude oil is distilled into lighter-weight products such as gasoline, diesel, and jet fuel. The heavy material is reacted to form coke and lighter products. The porous coke may be a good material for storing CO2, and its storage capacity may be improved by the addition of biomaterials to the heavy coker feed. The student on this project may run Hg injection capillary pressure and thermal-gravimetric analyses on coke samples as well as produce coke samples from bioadditives in TU’s pilot-plant-scale delayed coker.

The Iski Lab uses Electrochemical Scanning Tunneling Microscopy (EC-STM) which is a technique that measures the physical height of conductive surfaces under a liquid layer and in an ambient environment to better understand surface interactions in biologically relevant conditions. This investigation will focus on the EC-STM study of simple amino acids, and the means by which these molecules interact with a Au(111) surface. Using EC-STM under relevant experimental conditions, previous studies have shown that the amino acids have a considerable interaction with the underlying surface. However, the adsorption mechanism and molecular orientation are still key questions that have yet to be answered and would be necessary to move in the direction of using these systems as biocatalysts. Day to day work activities would include wet chemistry, using the microscope, setting up external EC cells for potentiostat testing, and simple computer programming for the modeling of the molecules. My lab provides a unique opportunity to learn about physics, physical chemistry, nanotechnology, and materials chemistry in an effort to gain a better understanding of how simple systems may be used in a stepwise manner to develop efficient and alternative methods for energy production.

A new approach for assembling and integrating multi-gene pathways into the nuclear genome of microalgae using CRISPR-Cas9 [16] is the focus of this project, which will study the assembly and integration of complex multi-gene biosynthetic pathways into the nuclear genome of the microalgae species Chlamydomonas reinhardtii.  The potential of algae-based biofuels [17] and protein therapeutics [18] is well documented, but in order to achieve its full potential, genetic engineering is needed to increase the production of target metabolites to desirable levels. Although recombinant protein expression in the microalgae has recently become more robust, the assembly and expression of complex multi-gene biosynthetic pathways in microalgae has yet to be fully accomplished and is a significant step in our ability to engineer microalgae metabolite production for the production of commercially important products [19], [20]. Thus we hypothesize that based on the successful development of similar methods in other species, an efficient nuclear multi-gene assembly and integration method can be developed co C. reinhardtii.  Biosynthetic pathways consisting of one to four genes will be assembled using homologous recombination in the yeast strain Saccharomyces cerevisiae and integrated into the C. reinhardtii nuclear genome using CRISPR-Cas9.  Multi-gene biosynthetic pathways of increasing complexity will be studied systematically. Pathways to be assembled include well studied selection markers and reporter genes and the biosynthetic pathway for the bioplastic polyhydroxybutyrate (PHB) [21]. Once integrated into the nucleus, the genetically engineered strains will be tested using a variety of methods to determine the levels of gene expression and the production level of PHB. The proposed project will provide important insights into the assembly and expression of biosynthetic pathways in microalgae and result in the development of an important tool for genetically modifying the nuclear genome of C. reinhardtii. These insights and the resulting methodology will aid current efforts to produce biofuels from microalgae, enhance our ability to produce therapeutic proteins in microalgae, and be an effective new tool for genetically engineering higher plants and other strains of microalgae.

Wind turbine blades are exposed to several environmental conditions. Thus, they are prone to damage which can affect their performance significantly. Current research at TU is investigating the leading edge erosion of wind turbine blades by water droplets experimentally. The current research approach is assuming that the falling droplets are perfectly spherical and are not influenced by any local turbulence or vortex shedding. However, we have reason to believe that the droplets are affected by this turbulence thus require a way to measure and simulate this phenomenon in a controlled setting. The proposed SALT project focuses on measuring the falling droplets’ size and shape using (Particle Image Velocimetry) PIV in both “static” flow and “simulated” flow and compare results.

Many lithium-ion batteries use liquid electrolytes, which provide excellent performance but can increase the flammability of the battery. Switching to a solid polymer electrolyte (SPE) would potentially reduce these safety risks, but some performance limitations must be overcome. Many of the methods to create SPE films with enhanced conductivities have disadvantages, such as laborious multi-step procedures, low degrees of control regarding porosity, high thermal treatment temperatures, and low yields. The Lamar group has recently developed a method to create PEO-LiSO₃CF₃ (PEO-LiOTf) films with enhanced conductivity via a selective extraction of nanophase-separated materials. In this approach, selective extraction of a hydrocarbon nanofiller creates surface pores and bulk cavities that allow for enhanced transport of ions within the PEO-LiOTf film. This project will be a follow-up on an initial investigation which observed that different nanofiller compounds result in very different film properties. A measurement technique called small-angle x-ray scattering (SAXS) will be used to track the changes in nanofiller crystallinity and pore size as it changes over time, leading to improved selection of nanofiller compounds and doping concentrations. Additionally, the student will be assisting Dr. Weston with testing the new SAXS instrument and preparing a collection of ‘model’ samples for use in a hands-on workshop regarding the instrument.

One of the major challenges for new types of solar cells is to transition from “lab-scale” fabrication methods to “industrial-scale” methods. Due to the fundamental properties of electrodeposition, methods developed in the lab are much easier to scale than other thin-film technologies. In this project, we are evaluating the electrodeposition of thin films relevant for perovskite solar cells onto transparent and flexible base electrodes. The conditions necessary for uniform and reproducible depositions will be analyzed along with the evaluation of sequential electrodeposition strategies

Elastocaloric materials are solids with a pronounced coupling between temperature and mechanical deformation, due to the latent heat of a solid-to-solid phase transformation (akin to the latent heat of the phase change between ice and water). When an elastocaloric is repeatedly pushed and pulled, it can be used as a solid-state refrigerator, with the potential for significant energy savings. Since these materials are mechanically cycled, it is important to know how they respond to cracks. However, the solid-to-solid phase change in the materials complicates their cracking response, and the crack growth response of these materials has only been characterized for a select few temperature points, instead of the wide range of temperatures that they experience. Using a unique thermomechanical capability that is being developed at TU, this work will seek insights about the behavior of cracks in elastocaloric materials while they undergo repeated mechanical loads across a wide range of temperatures.

Heavy metal impurities are toxic even at low concentrations (parts per billion) and can cause health issues if not removed from crude oil. Metals including arsenic, barium, cadmium, chromium, copper, lead, tin, vanadium, zinc, and mercury are present as stable organometallic compounds in crude oil. Although several methods exist to remove metals from crude oil, only a few have been used industrially due to various limitations. For instance, the solvent extraction process reduces the yield of the end product substantially, whereas distillation only concentrates the metals in the heavier fractions (or petcoke). Therefore, there is still a need for processes that can lower crude oil’s sulfur and metal contents. We propose testing hemp-derived bio-adsorbents for this process as a cheaper and greener alternative. Post-extracted hemp biomaterial will be thermally converted into biochar, a precursor to bio-adsorbents, and then chemically modified to trap sulfur and heavy metal impurities from crude oil.